Re: [PATCH v5 10/11] intel_sgx: glue code for in-kernel LE

From: Jarkko Sakkinen
Date: Sat Nov 25 2017 - 07:52:36 EST


On Fri, Nov 17, 2017 at 03:07:05PM -0800, Darren Hart wrote:
> On Mon, Nov 13, 2017 at 09:45:27PM +0200, Jarkko Sakkinen wrote:
> > Glue code for hosting in-kernel Launch Enclave (LE) by using the user
> > space helper framework.
> >
> > Tokens for launching enclaves are generated with by the following
> > protocol:
> >
> > 1. The driver sends a SIGSTRUCT blob to the LE hosting process
> > to the input pipe.
> > 2. The LE hosting process reads the SIGSTRUCT blob from the input
> > pipe.
> > 3. After generating a EINITTOKEN blob, the LE hosting process writes
> > it to the output pipe.
> > 4. The driver reads the EINITTOKEN blob from the output pipe.
> >
> > If IA32_SGXLEPUBKEYHASH* MSRs are writable and they don't have the
> > public key hash of the LE they will be updated.
> >
>
> A few nits throughout to keep in mind:
>
> * #includes in alphabetical order in general
> * function local variables declared in order of decreasing line length
> * don't insert newlines where coding_style doesn't compel you to
>
> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> > -
> ...--
> > diff --git a/drivers/platform/x86/intel_sgx/sgx_le.c b/drivers/platform/x86/intel_sgx/sgx_le.c
> > new file mode 100644
> > index 000000000000..d49c58f09db6
> > --- /dev/null
> > +++ b/drivers/platform/x86/intel_sgx/sgx_le.c
> > @@ -0,0 +1,313 @@
> ...
> > +#include <linux/file.h>
> > +#include <linux/fs.h>
> > +#include <linux/kmod.h>
> > +#include <linux/mutex.h>
> > +#include <linux/wait.h>
> > +#include <linux/pipe_fs_i.h>
> > +#include <linux/sched/signal.h>
> > +#include <linux/shmem_fs.h>
> > +#include <linux/anon_inodes.h>
>
> alphabetical order
> ...
> > +static int sgx_le_create_pipe(struct sgx_le_ctx *ctx,
> > + unsigned int fd)
> > +{
> > + struct file *files[2];
> > + int ret;
> > +
> > + ret = create_pipe_files(files, 0);
> > + if (ret)
> > + goto out;
>
> Fairly inconsistent in the use of the goto out: model and returning
> inline where there is no cleanup to be done. Whatever you do, please be
> consistent within the file.
>
> If there is no cleanup to do, a local return is fine.

It is cruft that I haven't remembered to clean up eg there used to be
clean up. Thanks for spotting that.

/Jarkko